Observations of Water Masers Associated with the Proto-Planetary Nebula Candidate IRAS 19296+2227
Abstract
We present the first VLBI observations of the 616-523, 22-GHz H_2O maser emission associated with a proto-planetary nebula candidate. Three epochs of observation of the water masers towards IRAS 19296+2227 were obtained with the Very Long Baseline Array operated by the National Radio Astronomy Observatory. These observations show that the water masers are distributed over a 40 milliarcsecond, arc-like structure covering a limited velocity range of ~ 4 km s(-1) . It is unclear whether the masers reside in a residual circumstellar shell or in a region shocked by a PN fast wind. Over the 40 days spanning Epochs 1 and 3, we have measured an average proper motion of 12.6 +/- 5.7 km s(-1) indicating that the masers are probably not in a high velocity outflow.
- Publication:
-
American Astronomical Society Meeting Abstracts #194
- Pub Date:
- May 1999
- Bibcode:
- 1999AAS...194.5004M